However, he added that new cast member Darren Criss is "certainly an option".

"I'm not sure how soon I want to [reveal] that information because it's such a big storyline of the year," he said. "I want there to be some surprises. But Darren has a major, major arc."

Murphy continued: "He sort of becomes Kurt's mentor and then maybe love - he had to leave his own school because of bullying and goes to an all-boys academy and finds acceptance because that school has a no-bullying, zero-tolerance policy. So Kurt really admires and respects him. [Criss] plays someone who's one year older than Chris's character, so he's the old pro."